Field
Embodiments of the present disclosure generally relate to a methods of forming dielectric materials on a substrate. More specifically, embodiments provided herein relate to process flow for forming high quality flowable chemical vapor deposition (FCVD) films.
Description of the Related Art
In semiconductor processing, devices are being manufactured with continually decreasing feature dimensions. Often, features utilized to manufacture devices at these advanced technology nodes include high aspect ratio structures and it is often necessary to fill gaps between the high aspect ratio structures with an insulating material. Examples where insulating materials are utilized for gap fill applications include shallow trench isolation, inter-metal dielectric layers, passivation layers, patterning applications, etc. As device geometries shrink and thermal budgets are reduced, void-free filling of high aspect ratio spaces becomes increasingly difficult due to limitations of existing deposition processes.
FCVD films may be utilized for high aspect ratio gap fill applications as the films exhibit good conformity, step coverage, and the ability to adequately fill high aspect ratio (HAR) spaces (HAR>10:1). However, FCVD films generally exhibit low density as deposited when compared to thermally deposited oxides. Moreover, high temperature annealing processes at temperatures greater than about 500 degrees Celsius, such as greater than about 1000 degrees Celsius, are often utilized in conventional FCVD processes to improve the film density. Such temperatures are often beyond the thermal budgets of device materials and may not be suitable for desired applications. In addition, high temperature annealing processes may cause film shrinkage and create undesirable tensile stress within the films which may result in device defects. Finally, conventional FCVD processes often suffer from queue time inefficiencies when a predominantly oxide containing dielectric film is desired.
Thus, there is a need for improved processes for forming FCVD films.